1. Field of the Invention
A dual seal gasket specifically configured to seal the joint between adjacent concrete pipes.
2. Description of the Prior Art
Numerous efforts have been made to provide a pipe connection comprising a penetrating pipe and a receiving pipe. Various retaining rings or sealing rings are exployed which extend into the inner side of the receiving pipe ending a short distance from the free end of the pipe wherein the diameter of the retaining ring being substantially equal to the inner diameter of the receiving pipe.
Such pipe connections are known but present particular disadvantages. The retaining ring for instance can be easily damaged when the pipe with ring strikes the surface of the ground at a high angle. Moreover the ring, in case of such a fall, may be slightly displaced whereby the clamping effect is impaired.
An effort to obviate these difficultes because the sealing body part only cooperates partially with the bottom of the retaining ring and the latter cooprates resiliently and clampingly with the outer side of the receiving pipe part is disclosed in U.S. Pat. No. 3,857,589.
As shown, the sealing body acts as a resilient member supporting the retaining ring, while the resilient clamping permits a certain displacement of the retaining ring. The local cooperation between the bottom of the ring and the sealing body part is obtained by constructing the sealing body part such that it ends in a point, or by causing the sealing body part to cooperate by two protruding ribs with the bottom and by causing the part of the sealing body, situated between these two ribs to end at some distance from the bottom.
Unfortunately this as well as others shown in U.S. Pat. Nos. 2,832,614; 3,315,971; 3,656,771; 4,084,828; 3,857,589; 3,520,541; 3,515,396; 3,675,685, still exhibit various shortcomings. Thus a need still exist for a reliable sealing means.